If you're looking for a simple solution to record audio on your Xperia X10 (SO-01B), the SoundRecorder wrapper developed by pline.co.jp might be what you're looking for. This Android app is free to download and use, and it launches the SoundRecorder app on your device. However, it's worth noting that this app won't work if your device doesn't have the SoundRecorder Class or Activity.

Once you've recorded audio, SoundRecorder saves it in either *.3gpp or *.amr format on your device's /sdcard. You also have the option to rename *.3gpp files to *.3gp for audio/3gpp mime-type, although audio/amr is recommended. Overall, this app provides a simple solution for Xperia X10 (SO-01B) users who need to record audio.